Preview.SurfaceProvider
public
static
interface
Preview.SurfaceProvider
androidx.camera.core.Preview.SurfaceProvider |
A interface implemented by the application to provide a Surface
for Preview
.
This interface is implemented by the application to provide a Surface
. This
will be called by CameraX when it needs a Surface for Preview. It also signals when the
Surface is no longer in use by CameraX.
Summary
Public methods | |
---|---|
abstract
void
|
onSurfaceRequested(SurfaceRequest request)
Called when a new |
Public methods
onSurfaceRequested
public abstract void onSurfaceRequested (SurfaceRequest request)
Called when a new Surface
has been requested by the camera.
This is called every time a new surface is required to keep the preview running. The camera may repeatedly request surfaces throughout usage of a Preview use case, but only a single request will be active at a time.
A request is considered active until it is fulfilled, marked as 'will not complete', or cancelled by the camera. After one of these conditions occurs, a request is considered completed.
Once a request is successfully completed, it is guaranteed that if a new request is
made, the Surface
used to fulfill the previous request will be detached from the
camera and SurfaceRequest.provideSurface(Surface, Executor, Consumer)
will be
invoked with a SurfaceRequest.Result
containing
SurfaceRequest.Result.RESULT_SURFACE_USED_SUCCESSFULLY
.
Example:
class MyGlSurfaceProvider implements Preview.SurfaceProvider { // This executor must have also been used with Preview.setSurfaceProvider() to // ensure onSurfaceRequested() is called on our GL thread. Executor mGlExecutor; @Override public void onSurfaceRequested(@NonNull SurfaceRequest request) { // If our GL thread/context is shutting down. Signal we will not fulfill // the request. if (isShuttingDown()) { request.willNotProvideSurface(); return; } // Create the surface and attempt to provide it to the camera. Surface surface = resetGlInputSurface(request.getResolution()); // Provide the surface and wait for the result to clean up the surface. request.provideSurface(surface, mGlExecutor, (result) -> { // In all cases (even errors), we can clean up the state. As an // optimization, we could also optionally check for REQUEST_CANCELLED // since we may be able to reuse the surface on subsequent surface requests. closeGlInputSurface(surface); }); } }
Parameters | |
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request |
SurfaceRequest : the request for a surface which contains the requirements of the
surface and methods for completing the request.
|